New Aluminium Bell Housing

 

I made the new aluminium bell housing this afternoon. It was a little tricky, as I didn't have a really accurate way of measuring the steel version, and I wanted to get the alignment spot on! However, I got there in the end and the result is great.

 

 

As you can see from these two pictures the weight saving is 12.6Kg which in the grand scheme of things probably doesn't seem that much, but the machine is a little too heave, particularly at the rear end where the engine is mounted, so any saving is worth while, especially as there is still more weight to be added yet!

 

The finished aluminium version with acrylic inspection/tacho hatch.

The inspection/tacho hatch is so I can fire my laser tacho through the window and take an accurate RPM reading if required.

3 Axis Foot Parts

 

Started machining some of the 3 axis foot parts today, above are the 16mm spacer rings, and below are the 3mm Load Cell protector caps / anti-rotation washers.

Main Pump Removed!

 

Well this is something I really didn't want to do, but seeing that I have the gear pump off and I would like to remake the bell housing lighter, there is no option! Also I may look at checking the pump control circuit while its off, the bosch rep thinks it may have dirt in the control valve which is causing the occasional pulsating! Hmm..

20cc Gear pump

The new gear pump arrived which will deliver a higher flow through the cooling system, and hopefully keep the system cooler! The old gear pump produced a flow of between 20 and 36 lpm, this new pump should produce 30 to 55 lpm.

Ankle sensor modification

 

Having stripped down the first of the four axis legs, I decided to see how easy the modification to the ankle sensor would be. This modification brings the cable out of a small M8 cable gland to one side of the housing, currently the housing consists of two parts, but I can't bring the cable out in its original position in the new 3 axis leg design, so the idea is to drill across hole through the side of the housing into the switch chamber, then drill down through the back face to break into the side hole. The cable will then go through the M8 gland, through the side hole and into the chamber. The side hole will then be plugged with an M6 screw or something similar.

So far so good, the cross hole has been drilled to 5mm so it can be tapped and plugged to M6.

Job done, I just need to tap the M8 hole a little deeper and plug the side hole, but it looks like its going to work!

New 3 Axis leg strip down starts

 

I stripped off all of the fourth axis hardware today for the right anterior leg. This is a pretty risky move, and I've been procrastinating for some time as to whether or not to do this. But the pros for going back to a three axis leg far out weigh keeping the four axis design. If however it turns out that the four axis design would have been better I can always re-instate it, with a simpler design without the need for the belt driven encoder.

  

 

About 13Kg of parts removed including the ram, should save a significant amount of machine weigh plus help with leg position control having less weight at the tip of the leg.

Re-design starts, Cab removed, Hydraulics drained... again!

 

With the kind help of a colleague Phil Ashton we took the cab off the machine and started work on the new centre A frame for the new tank and cooler mounting brackets. The plan is to put the cab on a hinge system much the same as the rear bonnet, this way it provides easy access for machine maintenance. This is the start of a major re-design phase, which will include: New hydraulic tank, new cooler, new cooler position/mount, new diesel tank, filter re-position, battery re-position, new engine bell housing, Cab separation to name but a few!

New Pancake Load Cell design

 

This is the new load cell pancake sensor and one design for the leg without the fourth axis. I'm going to use this MDF mock up to test the sensors operation.

Pulsing Pump Pressure

The variable displacement pump has been playing up recently! When the pressure is reduced to idle, which should be about 14bar, sometimes the pump pulses at around 35 to 45 bar. I took a video of this happening so that I can show the bosch rep. I have checked various signals to the pressure relief valve etc but can't see anything wrong. I also cleared the 0.8mm orifice but again i don't think it was blocked.

Christina and the Mantis

 

My girlfriend Christina pays a welcome visit to the workshop :)